Peter O’Hara, managing director of Workplace Giving UK, which funds the Geared For Giving campaign, said: “MPs are the only group that we have addressed that have not responded to or understood the simple maths that makes charitable giving through pay a no-brainer for higher-rate tax payers.

“Every sector that the campaign has sought to target, including retail, fashion, legal, media and banking, has been hugely responsive to the logic, but MPs remain unmoved, and the Treasury is positively resistant to engaging with any of the proven mechanics for success.

“MPs and government departments need to lead by example. We are asking every MP in the country to consider making their charitable donations direct from their pay and then to help build awareness of the benefits of payroll giving among employers and employees in their constituency.”